Pollutant Information: Non Methane VOC

About Non Methane VOC

Category: Air pollutants

Non-methane volatile organic compounds (NMVOCs) are organic compounds, which differ widely in their chemical composition. These organic compounds are often grouped under the NMVOC label as the majority display similar behaviour in the atmosphere. NMVOCs are emitted to air as combustion products, as vapour arising from petrol and solvent use and from numerous other sources. Interest in NMVOC emissions has grown as their role in the photochemical production of ozone has been appreciated. The diversity of processes which emit NMVOCs is huge, covering not only many branches of industry, but also transport, agriculture and domestic sources. The two largest sources of 2015 NMVOC emissions are industrial processes and product use (56% of 2015 emissions) and extraction and distribution of fossil fuels (17% of 2015 emissions). Only 14% of the NMVOC emissions arise from combustion sources, the most significant of which is residential combustion. Natural emissions of NMVOCs are also reported, but are not included in the UK emission total, in accordance with UNECE guidelines. These natural sources are primarily emissions from forests. The NMVOC emission time series, presented in the plot below, shows an increase in emissions between 1970 and 1990 with minor peaks in 1973 and 1979, followed by a steady reduction in emissions during the 1990s and 2000s. The latter is largely a reflection of the increasingly stringent emission limits across a range of sectors. The UK is currently on track to meet the National Emission Ceilings Directive and Gothenburg Protocol targets in 2020, with emissions having fallen by 72% since 1990. Emissions will need to be reduced by a further 1% from 2015 to meet this 2020 target.